class EXA1
{  int add(int x,int y)
{        return x+y;
}
}
class EXB1  extends EXA1
{  int add(int x,int y)
{        return x-y;
}
}
public class ExtendsExercise1
{   public static void main(String args[])
{  EXA1 a=new EXA1();
    System.out.println(a.add(80,20));
    a=new EXB1();
    System.out.println(a.add(80,20));
}
}
